Composition for aqueous coating material and process for its production, and two-component curable aqueous coating material kit

A process for producing a composition for aqueous coating material, which comprises:

• reacting a fluorinated copolymer (B) comprising from 40 to 60 mol % of a structural unit of the formula (a1), from 3 to 50 mol % of a structural unit of the formula (a2) and from 4.4 to 37 mol % of a structural unit of the formula (a3) provided that the total mol % value of the respective structural units of the formulae (a1), (a2) and (a3) is from 80 to 100 with a dibasic acid anhydride in an organic solvent to esterify a part of the hydroxyl group in the structural unit of the formula (a3) to introduce a carboxyl group;
• adding a basic compound to neutralize at least a part of the carboxyl group with the basic compound;
• adding water;
• and
• removing the organic solvent to form the composition for aqueous coating material which comprises water, a synthetic resin dispersed or dissolved in the water, and which contains no organic solvent or an organic solvent in an amount of at most 10 mass % based on the total mass of the composition for aqueous coating material, wherein the synthetic resin comprises a fluorinated copolymer (A) comprising from 40 to 60 mol % of the structural unit of the formula (a1), from 3 to 50 mol % of the structural unit of the formula (a2), from 4 to 30 mol % of the structural unit of the formula (a3) and 1.4 to 6 mol % of a structural unit of the formula (a4) provided that the total mol % value of the respective structural units of the formulae (a1), (a2), (a3) and (a4) is from 80 to 100;
• wherein the synthetic resin:
• —CFX1—CX2X3— Formula (a1)
• provided that in the formula (a1), each of X1 and X2 which are independent of each other, is a hydrogen atom, a chlorine atom or a fluorine atom, and X3 is a chlorine atom, a fluorine atom or —CY1Y2Y3, wherein each of Y1, Y2 and Y3 which are independent of one another, is a hydrogen atom, a chlorine atom or a fluorine atom;
• provided that in the formula (a2), Ra is a hydrogen atom or a methyl group, R1 is a C1-12 alkyl group or a C4-10 monovalent alicyclic group, j is an integer of from 0 to 8, and k is 0 or 1;
• and
• provided that in the formula (a3), Rb is a hydrogen atom or a methyl group, R2 is a C1-10 alkylene group or a C4-10 bivalent alicyclic group, m is an integer of from 0 to 8, and n is 0 or 1, and
• provided that in the formula (a4), Rb and R2 are as defined in the formula (a3), respectively, R3 is a C2-10 alkylene group or a C4-10 bivalent alicyclic group, R4 is a hydrogen atom or —NHZ1Z2Z3, wherein each of Z1, Z2 and Z3 which are independent of one another, is a hydrogen atom, a C1-4 alkyl group or a C1-6 hydroxyalkyl group, provided that at least a part of R4 is required to be —NHZ1Z2Z3, p is an integer of from 0 to 8, and q is 0 or 1.